Human platelet lysate improves the growth and survival of cultured human pre-antral follicles.

RESEARCH QUESTION: How do platelet-rich plasma products like human platelet lysate (HPL) and umbilical cord plasma (UCP) affect the growth and survival of isolated human pre-antral follicles in vitro? DESIGN: Human pre-antral follicles (n = 724; mean diameter: 75 µm; range: 46-237 µm) were isolated from ovarian medulla donated by 14 patients undergoing unilateral oophorectomy for ovarian tissue cryopreservation. Follicles were encapsulated in 0.5% alginate and cultured for 8 days in media supplemented with 5% fetal bovine serum (FBS) (n = 171), 2.5% human serum albumin (HSA) (n = 159), 5% HPL (n = 223) or 5% UCP (n = 171). RESULTS: The survival probability was significantly higher in the group supplemented with HPL (80%) compared with the other three groups: FBS (54%, P < 0.001); HSA (63%, P = 0.004) and UCP (29%, P < 0.001). Surviving follicles in the UCP group had less defined follicular membranes and decompacted granulosa cell layers. The median growth of surviving follicles was significantly (P < 0.001) larger in the HPL group (73 µm) compared with any of the other three groups: HSA (43 µm); FBS (40 µm) UCP (54 µm). A descriptive analysis of follicular secretion of anti-Müllerian hormone and oestradiol did not reveal any difference between the groups. The detectability of follicular genes was high for AR (100%), AMHR2 (100%) and FSHR (76%), whereas few follicles expressed LHR (20%). CONCLUSION: Human platelet lysate significantly improved survival and growth of cultured human pre-antral follicles compared with FBS, HSA and UCP. The use of HPL is a valuable improvement to culture human pre-antral follicles but further studies will have to prove whether the superiority of HPL translates into better quality oocytes.

Anti-Müllerian hormone and live birth in unexplained recurrent pregnancy loss.

RESEARCH QUESTION: Is anti-Müllerian hormone (AMH) associated with live birth rate (LBR) in women with unexplained recurrent pregnancy loss (RPL)? DESIGN: Cohort study of women with unexplained RPL attending the RPL Unit, Copenhagen University Hospital, Denmark, between 2015 and 2021. AMH concentration was assessed upon referral, and LBR in the next pregnancy. RPL was defined as three or more consecutive pregnancy losses. Regression analyses were adjusted for age, number of previous losses, body mass index, smoking, treatment with assisted reproductive technology (ART) and RPL treatments. RESULTS: A total of 629 women were included; 507 (80.6%) became pregnant after referral. Pregnancy rates were similar for women with low and high AMH compared to women with medium AMH (81.9, 80.3 and 79.7%, respectively) (low AMH: adjusted odds ratio [aOR] 1.44, 95% confidence interval [CI] 0.84-2.47, P = 0.18; high AMH: aOR 0.98, 95% CI 0.59-1.64, P = 0.95). AMH concentrations were not associated with live birth. LBR was 59.5% in women with low AMH, 66.1% with medium AMH and 65.1% with high AMH (low AMH: aOR 0.68, 95% CI 0.41-1.11, P = 0.12, high AMH: aOR 0.96, 95% CI 0.59-1.56, P = 0.87). Live birth was lower in ART pregnancies (aOR 0.57, 95% CI 0.33-0.97, P = 0.04) and with higher numbers of previous losses (aOR 0.81, 95% CI 0.68-0.95, P = 0.01). CONCLUSION: In women with unexplained RPL, AMH was not associated with the chances of live birth in the next pregnancy. Screening for AMH in all women with RPL is not supported by current evidence. The chance of live birth among women with unexplained RPL achieving pregnancy by ART was low and needs to be confirmed and explored in future studies.

Ovarian reserve markers after discontinuing long-term use of combined oral contraceptives.

RESEARCH QUESTION: How early do the ovarian reserve markers anti-Müllerian hormone (AMH) and antral follicle count (AFC) normalize after discontinuation of the long-term use of combined oral contraceptives (COC). DESIGN: This was a prospective cohort study of 68 women with a history of long-term COC use. Serum AMH concentrations, ovarian volume and AFC were measured during COC use and serially in a 4-month period after discontinuing COC: 1 and 2 weeks after discontinuation, and on cycle day 2-5 during three consecutive menstrual cycles. Changes in AMH and AFC were investigated using linear mixed models of repeated measurements adjusted for relevant covariates. RESULTS: Mean age was 29.4 years and mean duration of COC use 8.0 years. Baseline median AMH concentrations during COC use of 13 pmol/l (interquartile range [IQR] 8.4-22 pmol/l) increased to a median of 22.5 pmol/l (IQR 11-37 mol/l) 3 months after discontinuation. The estimated average increase was 53% (95% confidence interval [CI] 1.40-1.68, P < 0.001). AFC increased from a median value of 17 (IQR 11-25) to 24 (IQR 17-34). The estimated average increase was 41% (95% CI 1.30-1.52, P < 0.001). Ovarian volume increased from 2.4 to 5.8 ml (P < 0.001). The ovarian reserve markers increased continuously from baseline measurements until 2 months after discontinuation. Thereafter a plateau was reached. CONCLUSION: After discontinuation of COC, AMH increased by 53% and AFC by 41%, with values returning to normal within 2 months. This study provides clinicians with the highly relevant knowledge that AMH and AFC can be measured 2 months after discontinuation of COC without having to account for their influence.

Ovarian reserve markers and endocrine profile during oral contraception: Is there a link between the degree of ovarian suppression and AMH?

The ovarian reserve markers anti-Müllerian hormone (AMH) and antral follicle count (AFC) are suppressed in varying degree during the use of combined oral contraceptives (COC). Further, long-term use of COC can mask a condition of premature ovarian insufficiency. A desirable clinical tool that could distinguish true low ovarian reserve markers from COC-induced low levels during use of COC is warranted. The aim of this multicenter study including 235 COC users was to assess whether low age-adjusted AMH levels during COC use were linked to concomitant low levels of LH, FSH, estradiol and androgens - as a potential future tool to differentiate between 'false', COC-induced low AMH levels vs. true low AMH. Study population and methods: In total, 235 COC users from the general population aged 19-40 years were included. AMH, AFC and a reproductive hormonal profile were measured during COC intake. Age-adjusted AMH levels (Z-scores) were calculated from a comparison group of 983 non-users of COC. Differences in hormonal profile were tested between women with low versus high age-adjusted AMH-quartiles based on non-parametric Wilcoxon rank sum tests. The outcomes of interest were levels of gonadotropins, estradiol and androgens according to the four the age-adjusted AMH quartiles to find out if women with low age-adjusted AMH levels had a stronger gonadotropin suppression compared with women with higher age-adjusted AMH levels. Mean age of COC users was 30.2 years (SD 3.8), median AMH 14 pmol/l (inter-quartile range (IQR) 8.7-23)), median AFC 16 (IQR 11-25). We found no significant differences across the age-adjusted AMH quartiles in either the levels of gonadotropins, estrogens or androgens, respectively. Thus, the degree of suppression of FSH, LH, androgens and estradiol are unlikely to be a useful tool to differentiate between false low and true low ovarian reserve markers during COC use. Presently, there seems to be no alternative to withdrawal of the COC and to re-test the ovarian reserve after 2-3 months. Trial registration Trial no. NCT02785809 (www.clinicaltrials.gov).

Ovarian reserve markers in women using various hormonal contraceptives.

Objectives: The aim of the study was to assess whether the ovarian reserve markers anti-Müllerian hormone (AMH) and antral follicle count (AFC) were lower among women using the progestin-only pill (POP) or levonorgestrel-releasing intrauterine system (LNG-IUS) and similar to the decrease observed in combined oral contraceptive (COC) pill users.Methods: This retrospective study comprised 565 hormonal contraceptive users (COC, POP, LNG-IUS or contraceptive vaginal ring) and 983 non-hormonal contraceptive users, who were seen in two Danish fertility assessment and counselling clinics between 2015 and 2019. Adjusted multiple regression analysis was used to examine the differences in AMH and AFC between hormonal and non-hormonal contraceptive users.Results: Compared with non-hormonal contraceptive users, AMH was 31.1% lower among COC users [95% confidence interval (CI) -39.6%, -25.9%; p < 0.001], 35.6% lower among POP users (95% CI -49.0%, -18.6%; p < 0.001) and 17.1% lower among LNG-IUS users (95% CI -31.4%, 0.002%; p = 0.052); no significant differences were seen among vaginal ring users. Compared with non-hormonal contraceptive users, AFC was 31.3% lower among COC users (95% CI -35.0%, -25.3%; p < 0.001) and 29.7% lower among POP users (-39.1%, -17.9%; p < 0.001); no significant differences were seen among LNG-IUS or vaginal ring users. Ovarian volume was more than 50% reduced among COC and vaginal ring users (p < 0.001) but was unchanged among POP and LNG-IUS users.Conclusion: Assessment of ovarian reserve markers among users of all types of hormonal contraception should be interpreted cautiously and the type of contraceptive method considered.

The effect of preoperative cognitive impairment and type of vascular surgery procedure on postoperative delirium with associated cost implications.

OBJECTIVE: Postoperative delirium (POD) has a high prevalence among vascular surgery patients, increasing morbidity, mortality, and length of stay. We prospectively studied preoperative risk factors for delirium that can be assessed by the surgical team to identify high-risk patients and assessed its impact on hospital costs. METHODS: There were 173 elective vascular surgery patients assessed preoperatively for cognitive function using the Montreal Cognitive Assessment (MoCA) and the Confusion Assessment Method for POD, which was verified by chart and clinical review. Demographic information, medications, and a history of substance abuse, psychiatric disorders, and previous delirium were prospectively recorded. An accompanying retrospective chart review of an additional 434 (elective and emergency) vascular surgery patients provided supplemental cost information related to sitter use and prolonged hospitalization secondary to three factors: delirium alone, dementia alone, and delirium and dementia. RESULTS: Prospective screening of 173 patients (73.4% male; age, 69.9 ± 10.97 years) identified that 119 (68.8%) had MoCA scores <24, indicating cognitive impairment, with 7.5% having severe impairment (dementia). Patients who underwent amputation had significantly (P < .000) lower MoCA scores (17 of 30) compared with open surgery and endovascular aneurysm repair patients (23.7 of 30). The incidence of delirium was 11.6% in the elective cohort. Regression analysis identified predictors of delirium to be type of surgical procedure, including lower limb amputation (odds ratio [OR], 16.67; 95% confidence interval [CI], 3.41-71.54; P < .000) and open aortic repair (OR, 5.33; 95% CI, 1.91-14.89; P < .000); cognitive variables (dementia: OR, 5.63; 95% CI, 2.08-15.01; P < .001); MoCA scores ≤15, indicating moderate to severe impairment (OR, 6.13; 95% CI, 1.56-24.02; P = .02); and previous delirium (OR, 2.98; 95% CI, 1.11-7.96; P = .03). Retrospective review (N = 434) identified differences in sitter needs for patients with both delirium and dementia (mean, 13.6 days), delirium alone (mean, 3.9 days), or dementia alone (mean, <1 day [17.7 hours]). Fifteen patients required >200 hours (8.3 days), accounting for 69.7% of sitter costs for the surgical unit; 43.7% of costs were accounted for by patients with pre-existing cognitive impairment. CONCLUSIONS: POD is predicted by type of vascular surgery procedure, impaired cognition (MoCA), and previous delirium. Costs and morbidity related to delirium are greatest for those with impaired cognitive burden. Preoperative MoCA screening can identify those at highest risk, allowing procedure modification and informed care.

Concerns on future fertility among users and past-users of combined oral contraceptives: a questionnaire survey.

Objective: The combined oral contraceptive pill is the most preferred contraceptive method worldwide. Despite high life-time prevalence of infertility of 16-26%, scarce data about concerns of future fertility among COC users are available. We aimed to study whether COC usage induces concerns about fertility. Methods: Online questionnaire-based survey included 1283 current COC users and 1006 past users. The questionnaire covered knowledge and concerns of various aspects of fertility with respect to COC usage. Results: Significantly, more current users (66%) than past users (52%) had considered whether or not COC usage could affect future fertility (OR = 1.6, 95% CI 1.3-1.9). Nearly 50% of both groups believed COC usage could impair conception rates after discontinuation. Furthermore, 28% current vs. 19% past users believed COC could diminish the ovarian reserve more permanently. Conversely, 14% current and 11% past users believed that lack of ovulation could 'spare' the eggs (OR = 0.9, 95% CI 0.7-1.3). Significantly fewer current users (22%) vs. past users (35%) had heard, primarily by female friends, that a short break of 1-2 months during long-term COC usage was healthy, (OR 0.72, 95%CI = 0.56-0.92). Conclusions: Health care professionals prescribing hormonal contraception should be aware of misapprehensions and concerns of fertility among users of COC.

Low dose HP-hMG in an antagonist protocol for IVF in ovulatory and anovulatory patients with high AMH.

Women with high-AMH levels have an increased risk of ovarian hyperstimulation syndrome (OHSS). Studies have suggested that highly purified menotropin (HP-hMG) Menopur® reduces the risk. We, therefore, studied use of low-dose (112.5 IU/day) HP-hMG in ovulatory and anovulatory patients with high AMH (>32 pmol/L). The primary endpoint was the distribution of patients with appropriate, excessive, and inadequate response (5-14, ≥15, and ≤4 oocytes). Another endpoint was frequency of OHSS. Totally 115 women were included and 78 (67.8%) had an appropriate, 8 (7.0%) an excessive, and 29 (25.2%) an inadequate response. The number of oocytes was independent on AMH levels and ovulatory status but declined significantly with increasing bodyweight (R2 = 0.07, p < .01). The ongoing pregnancy rate per started cycle was 47.0%. Three (2.6%) developed OHSS, two had cancelation of the cycle and seven patients had GnRH agonist triggering to prevent OHSS. Selective use of a low dose of HP-hMG in patients with high levels of AMH provides 5-14 oocytes in more than two-thirds of the patients and is safe with low risk of OHSS. The number of aspirated oocytes was independent of AMH levels and ovulatory status, but inversely related to body weight.

Applying 'drought' to potted plants by maintaining suboptimal soil moisture improves plant water relations.

Pot-based phenotyping of drought response sometimes maintains suboptimal soil water content by applying high-frequency deficit irrigation (HFDI). We examined the effect of this treatment on water and abscisic acid (ABA) relations of two species (Helianthus annuus and Populus nigra). Suboptimal soil water content was maintained by frequent irrigation, and compared with the effects of withholding water and with adequate irrigation. At the same average whole-pot soil moisture, frequent irrigation resulted in larger soil water content gradients, lower root and xylem ABA concentrations ([X-ABA]), along with higher transpiration rates or stomatal conductance, compared with plants from which water was withheld. [X-ABA] was not uniquely related to transpiration rate or stomatal conductance, as frequently irrigated plants showed partial stomatal closure compared with well-watered controls, without differing in [X-ABA] and, in H. annuus, [ABA]leaf. In two P. nigra genotypes differing in leaf area, the ratio between leaf area and root weight in the upper soil layer influenced the soil water content of this layer. Maintaining suboptimal soil water content alters water relations, which might become dependent on root distribution and leaf area, which influences soil water content gradients. Thus genotypic variation in 'drought tolerance' derived from phenotyping platforms must be carefully interpreted.

The Fertility Assessment and Counseling Clinic - does the concept work? A prospective 2-year follow-up study of 519 women.

INTRODUCTION: The Fertility Assessment and Counseling (FAC) Clinic was initiated to provide women with information about their current fertility status to prevent infertility and smaller families than desired. The aim was to study the predictive value of a risk assessment score based on known fertility risk factors in terms of time to pregnancy. MATERIAL AND METHODS: Prospective cohort study of the first 570 women attending the FAC Clinic from 2011 to 2013 at Rigshospitalet, Denmark. A consultation included: risk assessment score sheet with items on infertility risk factors, anti-Müllerian hormone and ultrasound. The risk score was categorized as low, medium or high. After 2 years an email-based questionnaire was distributed regarding subsequent pregnancies. RESULTS: The follow-up questionnaire was answered by 519 women (91.1%). The mean age was 35 years and 38% were single at inclusion. The majority (67.8%, 352/519) tried to conceive within 2 years after attending the FAC Clinic. At follow up, 73.6% (259/352) had achieved a pregnancy, 21% (74/352) were still trying and 5.4% (19/352) had given up. Two-thirds (65%) with only low risk scores conceived spontaneously within 12 months, although this figure was only 32% for women with at least one high risk score (n = 82). Accordingly, presence of at least one high risk score reduced the odds of achieving a pregnancy within 12 months by 75% (OR 0.25, 95% CI 0.12-0.52). CONCLUSION: The new FAC Clinic concept seems usable and offers a tool for fertility experts to guide women on how to fulfill their reproductive life-plan.

Role of ALKBH1 in the Core Transcriptional Network of Embryonic Stem Cells.

BACKGROUND/AIMS: ALKBH1, an AlkB homologue in the 2-oxoglutarate and Fe2+ dependent hydroxylase family, is a histone dioxygenase that removes methyl groups from histone H2A. Studies of transgenic mice lacking Alkbh1 reveal that most Alkbh1-/- embryos die during embryonic development. Embryonic stem cells (ESCs) derived from these mice have prolonged expression of pluripotency markers and delayed induction of genes involved in neural differentiation, indicating that ALKBH1 is involved in regulation of pluripotency and differentiation. The aim of this study was to further investigate the role ALKBH1 in early development. METHODS: Double-filter methods for nitrocellulose-filter binding, dot blot, enzyme-linked immunosorbent assay (ELISA), immonocytochemistry, cell culture and differentiation of mouse ESCs, Co-IP and miRNA analysis. RESULTS: We found that SOX2 and NANOG bind the ALKBH1 promoter, and we identified protein-protein interactions between ALKBH1 and these core transcription factors of the pluripotency network. Furthermore, lack of ALKBH1 affected the expression of developmentally important miRNAs, which are involved in the regulation of NANOG, SOX2 and neural differentiation. CONCLUSION: Our results suggest that ALKBH1 interacts with the core transcriptional pluripotency network of ESCs and is involved in regulation of pluripotency and differentiation.

Estimation of Unrecorded Alcohol Consumption in Low-, Middle-, and High-Income Economies for 2010.

BACKGROUND: Consumption of unrecorded alcohol is prevalent, especially in low-income countries (LIC). Monitoring and reduction of unrecorded consumption have been asked for in the World Health Organization (WHO) global strategy to reduce the harmful use of alcohol. To date, only a few countries have installed monitoring systems, however. METHODS: As part of the WHO global monitoring, an expert survey using the nominal group technique, a variant of Delphi studies, was conducted to assess level and characteristics of unrecorded consumption in 46 member states. One hundred experts responded. Descriptive statistics and repeated analysis of covariance were used to analyze the data. RESULTS: The study showed feasibility of the chosen methodology to elicit information of unrecorded consumption with experts responding for 74% of the countries. Response rate was lower for LIC. Compared to prior WHO estimates, experts tended to estimate higher unrecorded consumption for LIC, and lower unrecorded consumption for high-income countries. Unrecorded consumption was seen as a financial, public health, and social problem by the majority of experts. Homemade alcohol was the most prevalent subcategory of unrecorded consumption globally. CONCLUSIONS: The chosen methodology was feasible, and new information about consumption of unrecorded consumption could be gathered. There is still a need for increasing efforts of national monitoring, especially in LIC.

Immunologic Abnormalities, Treatments, and Recurrent Pregnancy Loss: What Is Real and What Is Not?

Recurrent pregnancy loss, depending on the definition, affects 1% to 3% of women aiming to have a child. Little is known about the direct causes of recurrent pregnancy loss, and the condition is considered to have a multifactorial and complex pathogenesis. The aim of this review was to summarize the evaluation and the management of the condition with specific emphasis on immunologic biomarkers identified as risk factors as well as current immunologic treatment options. The review also highlights and discusses areas in need of further research.

Individual fertility assessment and pro-fertility counselling; should this be offered to women and men of reproductive age?

During the 1970s new contraceptive options developed and legal abortions became accessible. Family planning clinics targeting young women and men provided advice and assistance on contraception. Today, delayed childbearing, low total fertility rates and increasing use of social oocyte freezing create a need for pro-fertility initiatives. Three years ago we established a new separate unit: The Fertility Assessment and Counselling (FAC) clinic. The FAC clinic offers free individual counselling based on a clinical assessment including measurement of serum anti-Müllerian hormone and ovarian and pelvic sonography in women, sperm analysis in men, and a review of reproductive risk factors in both sexes. The FAC clinic includes a research programme with the goal to improve prediction and protection of fertility. Our first proposition is that clinics for individual assessment and counselling need to be established, as there is a strong unmet demand among women and men to obtain: (i) knowledge of fertility status, (ii) knowledge of reproductive lifespan (women) and (iii) pro-fertility advice. Addressing these issues is often more challenging than treating infertile patients. Therefore, we propose that fertility assessment and counselling should be developed by specialists in reproductive medicine. There are two main areas of concern: As our current knowledge on reproductive risk factors is primarily based on data from infertile patients, the first concern is how precisely we are able to forecast future reproductive problems. Predictive parameters from infertile couples, such as duration of infertility, are not applicable, diagnostic factors like tubal patency are unavailable and other parameters may be unsuitable when applied to the general population. Therefore, strict validation of reproductive forecasting in women and men from the general population is crucial. The second main concern is that we may turn clients into patients. Screening including reproductive forecasting may induce unnecessary anxiety through false positive predictions and may even result in overtreatment in contrast to the intended preventive concept. False negative findings may create false reassurance and result in postponement of conceptions.

Estimates of alcohol-related oesophageal cancer burden in Japan: systematic review and meta-analyses.

OBJECTIVE: To refine estimates of the burden of alcohol-related oesophageal cancer in Japan. METHODS: We searched PubMed for published reviews and original studies on alcohol intake, aldehyde dehydrogenase polymorphisms, and risk for oesophageal cancer in Japan, published before 2014. We conducted random-effects meta-analyses, including subgroup analyses by aldehyde dehydrogenase variants. We estimated deaths and loss of disability-adjusted life years (DALYs) from oesophageal cancer using exposure distributions for alcohol based on age, sex and relative risks per unit of exposure. FINDINGS: We identified 14 relevant studies. Three cohort studies and four case-control studies had dose-response data. Evidence from cohort studies showed that people who consumed the equivalent of 100 g/day of pure alcohol had an 11.71 fold, (95% confidence interval, CI: 2.67-51.32) risk of oesophageal cancer compared to those who never consumed alcohol. Evidence from case-control studies showed that the increase in risk was 33.11 fold (95% CI: 8.15-134.43) in the population at large. The difference by study design is explained by the 159 fold (95% CI: 27.2-938.2) risk among those with an inactive aldehyde dehydrogenase enzyme variant. Applying these dose-response estimates to the national profile of alcohol intake yielded 5279 oesophageal cancer deaths and 102,988 DALYs lost - almost double the estimates produced by the most recent global burden of disease exercise. CONCLUSION: Use of global dose-response data results in an underestimate of the burden of disease from oesophageal cancer in Japan. Where possible, national burden of disease studies should use results from the population concerned.

School choice & social stratification: how intra-district transfers shift the racial/ethnic and economic composition of schools.

The liberation model hypothesizes that school choice liberates students from underperforming schools by giving them the opportunity to seek academically superior schooling options outside of their neighborhoods. Subsequently, school choice is hypothesized to diminish stratification in schools. Data from one urban school district is analyzed to test these hypotheses. We specifically examine which factors influence the propensity for parents to participate in choice, and how school choice changes the racial/ethnic and economic composition of schools. We further examine how school choice influences similar changes within distinct sociogeographic areas within the district. We find that families who are zoned to more racially/ethnically and economically diverse schools in sociogeographically diverse areas are more likely to participate in school choice. We also find that intra-district choice is associated with a slight increase in social stratification throughout the district, with more substantial stratification occurring in the most demographically diverse areas and schools.

Kinetics of endogenous mouse FEN1 in base excision repair.

The structure specific flap endonuclease 1 (FEN1) plays an essential role in long-patch base excision repair (BER) and in DNA replication. We have generated a fluorescently tagged FEN1 expressing mouse which allows monitoring the localization and kinetics of FEN1 in response to DNA damage in living cells and tissues. The expression of FEN1, which is tagged at its C-terminal end with enhanced yellow fluorescent protein (FEN1-YFP), is under control of the endogenous Fen1 transcriptional regulatory elements. In line with its role in processing of Okazaki fragments during DNA replication, we found that FEN1-YFP expression is mainly observed in highly proliferating tissue. Moreover, the FEN1-YFP fusion protein allowed us to investigate repair kinetics in cells challenged with local and global DNA damage. In vivo multi-photon fluorescence microscopy demonstrates rapid localization of FEN1 to local laser-induced DNA damage sites in nuclei, providing evidence of a highly mobile protein that accumulates fast at DNA lesion sites with high turnover rate. Inhibition of poly (ADP-ribose) polymerase 1 (PARP1) disrupts FEN1 accumulation at sites of DNA damage, indicating that PARP1 is required for FEN1 recruitment to DNA repair intermediates in BER.

New insights into mechanisms behind miscarriage.

Sporadic miscarriage is the most common complication of early pregnancy. Two or three consecutive pregnancy losses is a less common phenomenon, and this is considered a distinct disease entity. Sporadic miscarriages are considered to primarily represent failure of abnormal embryos to progress to viability. Recurrent miscarriage is thought to have multiple etiologies, including parental chromosomal anomalies, maternal thrombophilic disorders, immune dysfunction and various endocrine disturbances. However, none of these conditions is specific to recurrent miscarriage or always associated with repeated early pregnancy loss. In recent years, new theories about the mechanisms behind sporadic and recurrent miscarriage have emerged. Epidemiological and genetic studies suggest a multifactorial background where immunological dysregulation in pregnancy may play a role, as well as lifestyle factors and changes in sperm DNA integrity. Recent experimental evidence has led to the concept that the decidualized endometrium acts as biosensor of embryo quality, which if disrupted, may lead to implantation of embryos destined to miscarry. These new insights into the mechanisms behind miscarriage offer the prospect of novel effective interventions that may prevent this distressing condition.

ALKBH1 is a histone H2A dioxygenase involved in neural differentiation.

AlkB homolog 1 (ALKBH1) is one of nine members of the family of mammalian AlkB homologs. Most Alkbh1(-/-) mice die during embryonic development, and survivors are characterized by defects in tissues originating from the ectodermal lineage. In this study, we show that deletion of Alkbh1 prolonged the expression of pluripotency markers in embryonic stem cells and delayed the induction of genes involved in early differentiation. In vitro differentiation to neural progenitor cells (NPCs) displayed an increased rate of apoptosis in the Alkbh1(-/-) NPCs when compared with wild-type cells. Whole-genome expression analysis and chromatin immunoprecipitation revealed that ALKBH1 regulates both directly and indirectly, a subset of genes required for neural development. Furthermore, our in vitro enzyme activity assays demonstrate that ALKBH1 is a histone dioxygenase that acts specifically on histone H2A. Mass spectrometric analysis demonstrated that histone H2A from Alkbh1(-/-) mice are improperly methylated. Our results suggest that ALKBH1 is involved in neural development by modifying the methylation status of histone H2A.